The present invention relates generally to plastic fasteners and more particularly to devices used in the dispensing of plastic fasteners.
In U.S. Pat. No. 4,039,078 to A. R. Bone, which is incorporated herein by reference, there are disclosed several different types of plastic fasteners (also commonly referred to in the art as plastic attachments). Each plastic fastener described in the patent is manufactured in an H-shaped configuration, with two shortened parallel cross-bars, or T-bars, being interconnected at their approximate midpoints by a thin, flexible filament which extends orthogonally therebetween. Each type of plastic fastener represented in the patent is shown as being fabricated as part of continuously connected ladder stock. In each instance, the ladder stock is formed from two elongated and continuous plastic side members, or rails, which are coupled together by a plurality of plastic cross-links, or filaments, the cross-links preferably being equidistantly spaced. The stock may be produced from flexible plastics material including nylon, polypropylene and other similar materials using conventional molding or stamping techniques. Ladder stock of the type described above is presently manufactured and sold by Avery Dennison™ Corporation of Pasadena, Calif. under the Plastic Staple® and Elastic Staple™ lines of plastic fasteners.
Ladder stock of the type described above is commonly wound onto a reel, or spool, which is sized and shaped to hold a supply of ladder stock that includes approximately 25,000 fasteners. In this manner, the reel can be used by a machine to continuously dispense a large quantity of individual fasteners, as will be described in detail below.
Either manually or with the aid of specifically designed devices, individual fasteners may be severed and dispensed from a supply of ladder stock to couple buttons to fabric, merchandising tags to articles of commerce, or, in general, any two desired articles.
Specifically designed devices for dispensing plastic fasteners are well known in the art. One well-known device for dispensing individual plastic fasteners from a reel of ladder-type fastener stock includes a pair of hollow needles which are adapted to penetrate through a particular item, a feed mechanism for advancing each rail of the supply of ladder stock into axial alignment behind the longitudinal bore defined by a corresponding hollow needle, a severing mechanism for severing a fastener to be dispensed through the pair of hollowed needles from the remainder of the ladder stock, and an ejection mechanism for ejecting the cross-bars of the severed fastener through the bores of the pair of hollowed needles and, in turn, through the particular item which is penetrated by the needles.
For example, in commonly assigned U.S. Pat. No. 5,433,366, which is incorporated herein by reference, there is disclosed a device for dispensing plastic attachments of the type which are formed as part of a roll of continuously connected ladder stock. In one embodiment, the device includes a pair of hollow slotted needles each having a tip, a rear end and a longitudinal axis. A feed wheel, placed proximate to the rear ends of the pair of needles, is used to feed individual attachments of a roll of ladder stock into the pair of needles through their respective rear ends at angles relative to the longitudinal axes thereof. Once inserted into the needles, an attachment is severed from the remainder of the ladder stock by a knife and is then expelled from the needles by a pair of ejector rods movable along the longitudinal axes of the pair of needles. Because attachments are fed into the pair of needles at angles relative to their longitudinal axes, no shuttling of the needles between an attachment feeding position and an attachment ejecting position is required. The pair of needles, the feed wheel, the knife, and the pair of ejector rods are all mounted on a vertically movable head member. An induction motor is used to move the head member between an attachment dispensing position and a withdrawal position. The vertical movement of the head member drives the operation of the feed wheel, the knife and the ejector rods.
Examples of some plastic fastener dispensing devices which are presently available in commerce are manufactured and sold by Avery Dennison™ Corporation of Pasadena, Calif. under the following names: the ST9000™, the Elastic Staple™ Single Needle System (SNS), the Elastic Staple™ Variable Needle System (VNS) and the Elastic Staple™ Single Needle System (SNS) Module.
As noted above, devices for dispensing plastic fasteners of the type described above are designed to cut the opposing rails of a supply of ladder stock at equidistant intervals to generate a plurality of individual plastic fasteners. The specific fixed distance, or spacing, between successive cuts in the rails of the ladder stock (i.e., the length of the cross-bar of each dispensed plastic fastener) is commonly referred to in the art as the pitch in which the device operates. As can be appreciated, each fastener dispensing device is typically designed to sever and eject plastic fasteners from a supply of ladder stock at a fixed pitch of 0.25 inches.
Although well known in the art, it has been found that fastener dispensing devices of the type described above suffer from some notable shortcomings.
As a first shortcoming, fastener dispensing devices of the type described above traditionally operate as a single stroke machine. Stated another way, activation of the device (e.g., through the depression of an actuation pedal) results in the ejection of a single plastic fastener. However, it has been found that certain applications require that a plurality of fasteners be dispensed in a rapid fire manner (e.g., whiskering applications in the jeans industry). Due to the inherent limitations associated with a single stroke machine, the plurality of fasteners can only be dispensed by repeatedly actuating the machine, which is a time-consuming and labor intensive process.
As a second shortcoming, fastener dispensing machines of the type described above operate at a fixed stroke speed of approximately 0.50 seconds/stroke. However, this stroke speed has been found to be unnecessarily slow when the device is used to dispense plastic fasteners through relatively thin materials. As a result, the productivity that is achieved using such a machine is limited.
As a third shortcoming, fastener dispensing machines of the type described above are not energy efficient. Specifically, the induction motor for the device requires a continuous supply of AC power which in turn renders the machine inefficient from a power consumption standpoint.
As a fourth shortcoming, fastener dispensing machines of the type described above are designed to receive a specified input voltage. Because electrical outlets in different countries provide different output voltages, each fastener dispensing machine is only available for use in selected locations, thereby limiting its usage.
As a fifth shortcoming, fastener dispensing machines of the type described above are stand alone devices (i.e., not linked with a computer). As a result, no computerized means are afforded to track and analyze historical information relating to usage of the device (e.g., quantity of fasteners dispensed, actuation rate per hour, etc.).